allocation_strategy: Leak the standard strategy
allocation_strategy: Leak the standard strategy

Some code may attempt to use it during finalization after "instance"
was destroyed.

Reported by Pekka:

/usr/include/c++/4.9.2/bits/unique_ptr.h:291:14: runtime error:
reference binding to null pointer of type 'struct
standard_allocation_strategy'
./utils/allocation_strategy.hh:105:13: runtime error: reference
binding to null pointer of type 'struct standard_allocation_strategy'
./utils/allocation_strategy.hh:118:35: runtime error: reference
binding to null pointer of type 'struct allocation_strategy'
./utils/managed_bytes.hh:59:45: runtime error: member call on null
pointer of type 'struct allocation_strategy'
./utils/allocation_strategy.hh:82:9: runtime error: member access
within null pointer of type 'struct allocation_strategy'

capturePointer/scylla,respu/scylla,bowlofstew/scylla,gwicke/scylla,respu/scylla,phonkee/scylla,scylladb/scylla,stamhe/scylla,kjniemi/scylla,kangkot/scylla,asias/scylla,kangkot/scylla,raphaelsc/scylla,rentongzhang/scylla,kjniemi/scylla,dwdm/scylla,senseb/scylla,duarten/scylla,guiquanz/scylla,tempbottle/scylla,senseb/scylla,kjniemi/scylla,dwdm/scylla,kangkot/scylla,aruanruan/scylla,aruanruan/scylla,tempbottle/scylla,victorbriz/scylla,glommer/scylla,asias/scylla,shaunstanislaus/scylla,avikivity/scylla,victorbriz/scylla,gwicke/scylla,wildinto/scylla,rluta/scylla,senseb/scylla,eklitzke/scylla,phonkee/scylla,tempbottle/scylla,avikivity/scylla,justintung/scylla,justintung/scylla,gwicke/scylla,scylladb/scylla,capturePointer/scylla,glommer/scylla,shaunstanislaus/scylla,avikivity/scylla,acbellini/scylla,stamhe/scylla,aruanruan/scylla,stamhe/scylla,bowlofstew/scylla,capturePointer/scylla,raphaelsc/scylla,duarten/scylla,dwdm/scylla,rentongzhang/scylla,wildinto/scylla,rluta/scylla,acbellini/scylla,acbellini/scylla,guiquanz/scylla,scylladb/scylla,rluta/scylla,shaunstanislaus/scylla,eklitzke/scylla,glommer/scylla,victorbriz/scylla,linearregression/scylla,guiquanz/scylla,eklitzke/scylla,duarten/scylla,linearregression/scylla,asias/scylla,linearregression/scylla,justintung/scylla,phonkee/scylla,wildinto/scylla,rentongzhang/scylla,scylladb/scylla,bowlofstew/scylla,respu/scylla,raphaelsc/scylla